Perishable items such as produce and meat are often transported in refrigerated trailers, railcars, or ocean-going containers that can be transported on ships, trains or trucks. Such cargo transport devices are typically equipped with a refrigeration unit which conditions the air inside the cargo space, thereby maintaining desired temperatures and humidities during transportation or storage. Refrigerated trailers, railcars and containers are typically configured so as to enclose a single, large cargo space. Their refrigeration units will accordingly maintain the entire cargo space at the same temperature and humidity unless the cargo area is somehow divided. However, when the perishable cargo does not fill the entire trailer, cooling the entire cargo area is unnecessary and costly. It causes unnecessary strain and wear on the refrigeration unit, increases fuel consumption, raises transportation costs, and lengthens the time necessary to cool the perishable cargo after any temperature aberration.
Movable partitions and bulkheads having a specialized construction which permits the cargo space of trailers, rail cars, and containers to be readily divided into sections of varying sizes are known. Such bulkheads and partitions have been widely used to separate cargo areas for multi-temperature transport. The structure and configuration of partition and bulkhead systems differ somewhat depending on whether they are being deployed in a trailer, railcar, or container. Partitions currently used in refrigerated truck trailers typically extend from floor to ceiling and are generally comprised of modular wall sections. The modular sections are often mounted in channels or grooves on the trailer floor, held in place by friction, or otherwise mechanically fastened in place so as to compartmentalize trailers and truck bodies for multi-temperature food distribution. The panels are used to divide the trailer or body both longitudinally, along the long axis of the trailer, and laterally, across the width of the trailer. Some partition systems include panels that can be readily removed and placed along the sidewall of the trailer when not in use.
Insulated bulkheads are panels that extend across the width of a trailer to form separate fore and aft cargo areas. Like partitions, insulated bulkheads allow a refrigerated hauler to carry two or more loads at different temperatures within the same trailer or cargo container. For instance, bulkheads may be used to separate fresh food products from frozen or dry goods. Bulkheads are optionally equipped with walk-through doors similar to those used in partitions to permit ingress to and egress from each conditioned cargo area. Due to the functional similarities between bulkheads and panels, the latter are sometimes referred to as bulkheads.